Columns, A Treatise On The Strength And Design Of Compression Members. PREFACE THIS work is approximately one-third of a Treatise on the same subject which the author submitted in 1916 to the University of London as a thesis for the degree of D.Sc. Engineering. The Thesis, on which the author spent nine years on, it consisted of three parts I. Historical II. Analytical III. Synthetical. Owing to the conditions now prevailing, it has been found impossible to get the complete work published, and in the present volume the historical portion, which consisted of a short summary of each important memoir, including all the published experimental work, has been replaced by a Bibliography. This Bibliography has been brought up to date, and includes, it is believed, all the more important original work on the subject. Articles of secondary interest and repetitions of work previously published have not been included. Parts II and III have been reproduced practically as they stood in the original, except that notes have been added, where necessary, to bring the work up to date. In Part II the author has endeavoured to give a perfectly general analysis, leading to the consideration of such particular cases as were suggested by his reading. Some of these are well known, others are new. In particular, he has considered the commonest of all cases in practice, the imperfect direction-fixed column. The analysis for flat-ended, and especially that for lattice-braced columns will, he hopes, prove of value. Unnecessary mathematical refinement has been avoided, and simple approximations sought for practical use. This work has brought to light a number of interesting new points. His reasons for the terminology, symbols, and definitions employed are fully set out in the Preface to the Thesis, and are not reproduced here. In Part III an attempt has been made to collate what has been done on the subject, In this portion of the work the author has endeavoured to sum up in a readable form the teachings of both theory and experiment.